Those are the plugs that came out of the back of the factory stereo in the 00-05 Monte they used for the tutorial. I want to install my stereo today but my harness that I bought only has the plug to connect to the grey connector, what's that black connector for? Is that for OnStar or the factory amp? If it's for the amp, I can just leave it unplugged, right?

 

yea i think thats for the onstar and the amp and i'm not positive but i don't think you can leave it unpluged but heres a link to the harness you need its where i got mine

without onstar--http://www.sonicelectronix.com/item_...-+GM09SRB.html

with onstar-- http://www.sonicelectronix.com/item_...GMOS2B11B.html

 

It's funny you posted that because I got that first harness (w/o onstar) and it doesn't have a plug for the smaller black plug in the picture I posted. It just has the large grey plug and a harness that plugs into the box (for the door chimes).